Catheter with formed guide wire ramp

ABSTRACT

A rapid exchange catheter comprises a guide wire lumen including a substantially sealed portion in which a lumen wall extends around an entire periphery thereof and a channel portion including a channel opening the lumen to an exterior of the catheter, wherein a width of the channel is less than a maximum width of the channel portion. A guide wire ramp extends into the channel portion, with the ramp extending further into the lumen of the channel portion as a distal end of the ramp is approached.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/437,281 filed May 7, 2009, now U.S. Pat. No. 8,388,876,which is a divisional of U.S. patent application Ser. No. 10/268,135filed Oct. 8, 2002, now U.S. Pat. No. 7,534,223, the entire disclosuresof which are incorporated herein by reference.

BACKGROUND INFORMATION

Endoscopic procedures for treating abnormal pathologies within thealimentary canal system and biliary tree (including the biliary, hepaticand pancreatic ducts) are increasing in number. The endoscope providesaccess to the general area of a desired duct using direct visualization.However, the duct itself must be navigated using a catheter inconjunction with fluoroscopy and guide wires.

If visualization of the common bile duct is desired, the guide wire isguided into the common bile duct and the catheter is advanced over theguide wire until the distal end thereof is positioned at a desiredlocation for delivery of the contrast media for fluoroscopicvisualization of the anatomical detail within the common bile duct.

Visualization may reveal selected areas within the common bile duct thatrequire treatment. To treat the selected areas, a different catheter istypically required, necessitating a catheter exchange. A catheterexchange typically involves removing the first catheter from theendoscope, over the guide wire, and advancing a second catheter over theguide wire to the desired treatment site. Once the guide wire is inplace relative to the targeted area, it is highly desirable to maintainthe position of the guide wire during subsequent catheter procedures,including during a catheter exchange procedure. If the guide wire movesduring such a procedure, the guide wire may need to be re-directedthrough the body ducts to the target site, which is often a difficultand time consuming task.

In addition to performing a catheter exchange procedure, it may bedesirable at times to perform a guide wire exchange procedure, forexample, when a first guide wire is too large to fit through a desiredbody duct, or otherwise lacks the characteristics desired for aparticular application. Under these circumstances, a physician may leavethe catheter in place and withdraw the first guide wire from thecatheter. The physician then inserts a second guide wire through thecatheter to the desired site. Thus, once the catheter has been properlypositioned at a target site, it is highly desirable to maintain theposition of the catheter during a guide wire exchange procedure so thatthe second guide wire may be guided directly to the desired site.

To maintain the position of the guide wire and/or catheter, a physiciantypically must grasp the proximal end of the guide wire and/or catheterwith one hand and perform the corresponding exchange with the other.This is difficult, and often results in the movement of the guide wireand/or catheter. Alternatively, additional devices such as guide wireextenders may be used. However, utilizing such additional devices addsto the complexity of and the time required for the exchange.

SUMMARY OF THE INVENTION

The present invention is directed to a rapid exchange catheter comprisesa guide wire lumen including a substantially sealed portion in which alumen wall extends around an entire periphery thereof and a channelportion including a channel opening the lumen to an exterior of thecatheter, wherein a width of the channel is less than a maximum width ofthe channel portion. A guide wire ramp extends into the channel portion,with the ramp extending further into the lumen of the channel portion asa distal end of the ramp is approached.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an exemplary embodiment of a catheter according to thepresent invention in a perspective view having a C-shaped channel andguide wire lumen for directing a guide wire along its shaft and forfacilitating rapid catheter exchange;

FIG. 2 shows a cross-sectional view of the catheter of FIG. 1 takenalong the line 2-2 thereof;

FIG. 3 shows a cross-sectional view of the catheter with the guide wireof FIG. 1 taken along the line 3-3 thereof;

FIG. 4 shows a cross-sectional view of the catheter with the guide wireof FIG. 1 taken along the line 4-4 thereof;

FIG. 5 shows a partially cross-sectional perspective view of thecatheter of FIG. 1 showing the formed guide wire ramp thereof takenalong the line 4-4 of FIG. 1; and

FIG. 6 shows a cross-sectional view of the catheter of FIG. 1 takenalong a longitudinal axis thereof.

DETAILED DESCRIPTION

FIGS. 1-6 show an exemplary embodiment of a catheter assembly 30according to the present invention. The catheter assembly 30 is used incatheter procedures for accessing targeted anatomical regions throughthe alimentary canal. The present invention incorporates features thatallow rapid exchange of a catheter by a single operator. The catheter ofthe present invention allows shorter length guide wires to be used,resulting in procedures which require less medical personnel, are lesstime consuming, and less costly. Additionally, the present invention isadaptable to a variety of catheter devices used for catheter procedureswithin the alimentary canal or any other is body lumen.

The catheter assembly 30 includes a catheter hub assembly 32 and acatheter 34, having a guide wire 36 passing through a guidewire lumen60, (shown in FIGS. 2 and 3) extending therethrough. The catheter 34includes a shaft 38 which has a proximal end 40, a C-channel 42, adistal tip region 44, a distal end 46 and various lumens described ingreater detail below. The catheter hub assembly 32 is operably connectedto a proximal end 40 of the shaft 38. The catheter hub assembly 32 ispreferably configured to couple to ancillary devices allowing access toa lumen within the shaft 38.

The shaft 38 may preferably be a generally tubular member having agenerally uniform outer shape at the proximal end 40. As would beunderstood by those of skill in the art, the shaft 38 may be sized forslidable passage through the lumen of an endoscope (not shown) orthrough a body lumen. The shaft 38 is preferably formed in an extrusionprocess, and may be formed of a polymeric material. In one embodiment,the preferred polymeric material is polytetrafluoroethylene, polyetherblock amide, nylon or a combination or blend of these. Catheters thatare contemplated include, but are not limited to, cannulas,sphincterotomes, cytology devices, and devices for stone retrieval andstent placement.

In a preferred embodiment, the shaft 38 may further include a distaltaper 48 that tapers to the distal tip region 44. Additionally, thedistal tip region 44 may, for example, include high contrast,color-coded distal markers 50. Finally, the distal end 46 may beradiopaque for fluoroscopic visualization of the distal tip region 44during a catheter procedure.

The guide wire lumen 60 extends through the catheter 34 from a proximalend to a distal end thereof. The C-channel 42 forms a portion (e.g., achannel portion) of the guide wire lumen 60, extending between a channelproximal end 52 and a channel distal end 54. The C-channel 42 serves tocontain, but not necessarily constrain, the guide wire 36 therein. Incontrast to some catheters that include channels that are substantially“U” shaped, the C-channel 42 is shaped substantially like a letter “C”.That is, sides of the C-channel extend inward from a maximum diameter topartially close the channel, as shown more clearly in FIGS. 4 and 5. The“C” shape allows radial removal of the guide wire 36 from the C-channel42 via a slot 42′ (e.g., a channel opening) extending between the wallsof the C-channel 42 and opening an interior of the guide wire lumen 60to an outside of the catheter 34. At the same time, the “C” shape of theC-channel, increases the overall strength of the shaft 38 compared withcatheters that have a “U” shaped channel. The increased strength of theshaft allows for greater force to be used in pushing the catheter 34into the body. The “C” shape of the C-channel also leaks less bodilyfluid as compared to catheters that have a “U” shaped channel.

In a preferred embodiment, the C-channel 42 is sufficiently large toallow unhindered radial removal of the guide wire 36 from the C-channel42 via the slot 42′. Further, the walls of the C-channel 42 and the slot42′ may be formed to be substantially equal in size to or slightlylarger than a diameter of a guide wire to be used with the catheter 34,as described in greater detail below. Although it is recognized that thechannel proximal end 52 may be located at any location distal of theproximal end 40 of the shaft 38, the channel distal end 54 is preferablylocated between 10 and 40 cm from the distal end 46 of the cathetershaft 38. The channel distal end 54 may-more preferably be locatedbetween 20 and 30 cm and, most preferably, approximately 25 cm from thedistal end 46.

As shown in FIG. 2, proximal to the channel proximal end 52 and abeginning at a sealed proximal portion 52′, the guide wire lumen 60 iscompletely sealed from an outside of the catheter 34. As shown in FIGS.4 and 5 and described more fully below, the portion of the guide wirelumen 60 between the channel proximal and distal ends 52, 54,respectively, (i.e., the C-channel 42) is open to the outside of thecatheter 34 via the slot 42′. The catheter 34 according to thisexemplary embodiment also includes ancillary lumens 56 and 58 which maybe used for a variety of purposes as would be understood by those ofskill in the art. FIG. 3 shows a guide wire 36 received in the distalportion of the guide wire lumen 60. Beginning at a sealed distal portion54′, this portion of the guide wire lumen 60 is also completely sealedfrom an outside of the catheter 34.

As would be understood by those of skill in the art, the ancillarylumens 56 and 58 may preferably extend longitudinally between theproximal end 40 and the distal end 46 of the shaft 38 so that they maybe used, for example, as injection lumens, allowing for high contrastmedia flow capability for bubble-free opacification and forvisualization of a desired anatomical region. Additionally oralternatively, the ancillary lumens 56 and 58 may, for example, be usedfor or serve as part of another ancillary device, such as a cutting wireor a retrieval balloon, etc.

The guide wire lumen 60 preferably extends longitudinally between theproximal end 40 and the distal end 46 of the shaft 38 in the preferredembodiment and is sized to receive the guide wire 36 slidably therein.As would be understood, the guide wire lumen 60 may be formed integrallywith the catheter shaft 38. Alternatively, the guide wire lumen 60 maybe a separate tubular member coupled to the catheter shaft 38. In onepreferred embodiment, the guide wire lumen 60 is a tubular member whichis located proximate the distal end 46 of the shaft 38. It isrecognized, though, that the guide wire lumen 60 may be formed anywherealong the shaft 38, and may comprise an extension of the shaft 38coupled to the distal end 46 thereof. Alternatively, it may run theentire length of the shaft 38.

As shown in FIGS. 5 and 6, a guide wire ramp 62 is formed by a portionof the wall above the guide wire lumen 60. As would be understood bythose of skill in the art, the ramp 62 may, for example, be formed by acut 62′ in a portion of the wall of the guide wire lumen 62 extending atan angle from the slot 42′ distally for a predetermined length. Thesubstantially triangular portion of the wall which will form the ramp 62may then be forced into the guide wire lumen 60 and formed as a ramp by,for example, application of a heated mandrel thereto. Those skilled inthe art will understand that this same structure may also be createdusing, for example, a direct molding process, ultrasonic welding orother known techniques. Thus, a pointed end 62″ of the ramp 62 willextend into the guide wire lumen 60 with the rest of the surface of theramp 62 extending upward therefrom to the outer surface of the catheter34.

In use, when a guide wire 36 has been previously positioned at a desiredlocation within the body, the physician simply inserts the proximal endof the guide wire 36 into the guide wire lumen opening at the distal endof the catheter 34 and slides the catheter 34 distally along the guidewire 36 while gripping the portion of the guide wire 36 extendingdistally of the distal end of the catheter 34 to retain the guide wire36 in the desired position. When the proximal end of the guide wire 36contacts the end 62″ of the ramp 62, the proximal end of the guide wireis deflected out of the guide wire lumen 62 through the slot 42′. Thephysician may then grasp the proximal end of the guide wire 36 andcontinue to slide the catheter 34 along the guide wire 36 until thedesired location is reached. As the guide wire 36 is received within theguide wire lumen 60 only along a short portion of the length of thecatheter 34, those skilled in the art will understand that the physicianmay at all times maintain his grasp on an exposed portion of the guidewire 36 to maintain it in position without the need for guide wireextenders.

If, thereafter, the catheter 34 is to be exchanged for another, thephysician simply draws the catheter 34 proximally along the guide wire36 while grasping the proximal end of the guide wire 36. When the distalend of the catheter 34 exits the body, the physician may grasp theportion of the guide wire 36 extending distally of the catheter 34 andremove the catheter 34 completely from the guide wire 36. The loadingprocess described above may then be repeated for the new catheter 34 tobe used. If, however, the physician wishes to exchange the guide wire 36while maintaining the catheter 34 in a desired position within the body,the following steps are performed. First, while grasping the proximalend of the catheter 34, the physician draws the guide wire 36 proximallyout of the guide wire lumen 60 and removes it from the body. Then, thenew guide wire 36 is inserted into the channel proximal end 52 and isfed through the guide wire lumen 60 through the C-channel 42 so that itdeflects the ramp 62 radially outward to allow the guide wire 36 to passthereunder, past the channel distal end 54 and out of the distal end ofthe catheter 34.

If a guide wire 36 has been inserted into the catheter 34 from theproximal end 40, through the C-channel 42 to the distal end 46 and thiscatheter 34 later needs to be exchanged while maintaining the guide wire36 in position, the physician grasps the proximal end of the guide wire36 to maintain it in position and slides the catheter 34 proximallyalong the guide wire 36 until the channel proximal end 52 is locatedoutside the body. The physician may then grasp the guide wire 36 via thechannel proximal end 52 or the slot 42′ and draw the proximal end of theguide wire 36 distally through the proximal portion of the guide wirelumen 60 while holding the distal portion of the guide wire 36stationary to maintain the position of the distal end of the guide wire36. When the proximal end of the guide wire 36 has been removed from theguide wire lumen 60, the catheter 34 may be drawn proximally from thebody with the guide wire 36 sliding out of the C-channel 42 via the slot42′. When the distal end of the catheter 34 is outside the body, thephysician grasps the portion of the guide wire 36 extending distally ofthe distal end of the catheter 34 and withdraws the catheter 34 from theguide wire 36.

Furthermore, as described above in regard to the exemplary embodiment,the strength of the catheter 34 is improved by cutting into only oneside of the slot 42′ to form the guide wire ramp 62. The guide wirelumen 60 and the C-channel 42 allow rapid exchange of the catheterassembly 30 when an alternative catheter is necessary during a medicalprocedure and make it possible to use a shorter guide wire 36 when theguide wire 36 exits the catheter 34 at the channel distal end 54 ratherthan the proximal end 40.

The present invention may be used, for example, in the treatment ofpathologies within a patient's biliary tree. Generally, for thetreatment of pathologies within the patient's biliary tree an endoscopicbiliary procedure is performed. Methods and devices for using biliarycatheters to perform such catheter procedures are disclosed in Weaver etal., U.S. Pat. No. 5,397,302 and Karpiel, U.S. Pat. No. 5,320,602, thedisclosures of which are expressly incorporated by reference herein. Inan endoscopic biliary procedure, the endoscope is introduced into themouth of a patient and guided down the patient's alimentary canalthrough the esophagus, the stomach, and past the pyloric sphincter ofthe stomach into the duodenum.

Prior to positioning the guide wire 36 within the patient, the catheterassembly 30 is fed into an endoscope and advanced to the opening of thebile duct under visual observation via the endoscope. The catheter 30 isthen advanced through the sphincter to enter the bile duct. At thispoint, a distal end of the guide wire 36 is inserted into the guide wirelumen 60 via the channel proximal end 52 and passed therethrough to thecatheter distal end 46. As the guide wire 36 passes through theC-channel 42, it encounters the ramp 62 and deflects the distal end 62″of the ramp 62 radially outward while passing through the lumen 60 tothe distal end 46 of the catheter 34. The distal end of the guide wire36 is then located within the bile duct where it may be guided to thetarget location using known techniques. As would be understood by thoseof skill in the art, if desired, the distal end of the guide wire 36 mayalternatively be fed into the guide wire lumen 60 through the catheterhub assembly 32 and into the proximal end 40 of the catheter 34 and fromthere to the distal end 46. However, this reduces the effectiveness ofthe rapid exchange features of the catheter 34 according to the presentinvention.

In one method, the guide wire 36 is advanced until its distal tip ispositioned within the target area in the biliary tree. For example, thedistal tip of the guide wire 36 may be guided through the orificeleading to the papilla of vater for access to the biliary tree. Thecatheter shaft 38 may then be advanced over the guide wire 36, trackingthe catheter assembly 30, until the catheter distal tip region 44 exitsthe distal end of the endoscope and is positioned within the desiredduct. In another method, the guide wire 36 and the catheter assembly 30are advanced together until the catheter distal end 44 is positioned atthe target area. In a third possible method, the catheter assembly 30 isfirst advanced to near the target area. The guide wire 36 may then beinserted when needed to further advance the catheter 34.

Once the guide wire 36 has been positioned at the target area, catheterprocedures may be performed. For example, contrast media, such asradiopaque dye, may be injected through the ancillary lumens 56 or 58into the common bile duct for visualization of the duct. After thedesired catheter procedure has been completed, the catheter assembly 30may be exchanged or removed from the endoscope, leaving the guide wire36 in position for other guide wire procedures.

The present invention is described with reference to the embodimentshown in FIGS. 1 to 6. One skilled in the art would understand thatchanges may be made in details, particularly in matters of shape, size,material and arrangement of parts. Accordingly, various modificationsand changes may be made to the embodiments without departing from thebroadest scope of the invention as set forth in the claims that follow.The specifications and drawings are, therefore, to be regarded in anillustrative rather than a restrictive sense.

What is claimed is:
 1. A catheter, comprising: a catheter shaft having aguidewire lumen extending therein, the catheter shaft having an outersurface; a first opening in the outer surface, the first opening beingdisposed proximally of a distal end of the catheter shaft; a secondopening in the outer surface, the second opening being disposedproximally of the first opening; a channel extending through the outersurface extending between the first opening and the second opening, thechannel defined by a first wall and a second wall; wherein an angled cutis formed in a portion of the first wall of the channel, the angled cutdefining a ramp member formed from a portion of the first wall; andwherein the ramp member extends into the guidewire lumen.
 2. Thecatheter of claim 1, wherein the angled cut extends from the channelproximally at an acute angle.
 3. The catheter of claim 1, wherein anancillary lumen is defined in the catheter shaft.
 4. The catheter ofclaim 1, wherein a distal portion of the catheter shaft includes one ormore visual marker members.
 5. The catheter of claim 1, wherein a distalportion of the catheter shaft includes a radiopaque marker.
 6. Thecatheter of claim 1, wherein the channel includes a C-shaped channel. 7.The catheter of claim 1, wherein the guidewire lumen has a diameter,wherein the channel has a channel width, and wherein the channel widthis smaller than the diameter of the guidewire lumen.
 8. The catheter ofclaim 1, wherein the channel includes a U-shaped channel.
 9. Thecatheter of claim 1, wherein the guidewire lumen has a diameter, whereinthe channel has a channel width, and wherein the channel width issubstantially the same size as the diameter of the guidewire lumen. 10.A method for manufacturing a catheter, the method comprising: providinga catheter shaft having a guidewire lumen; forming an elongated channelin the catheter shaft, the elongated channel defined by a first wall anda second wall, wherein a width of the elongated channel is less than adiameter of the guidewire lumen; cutting an angled slit in the firstwall to form a partially detached portion of a wall of the cathetershaft; and shifting the partially detached portion of the first wallradially into the guidewire lumen to form a guidewire ramp.
 11. Themethod of claim 10, wherein the guidewire ramp includes a first sidecorresponding to the first wall of the elongated channel in which theangled slit is cut and a second side corresponding to the angled slit.12. The method of claim 10, wherein cutting an angled slit in the firstwall to form a partially detached portion of the first wall of thecatheter shaft includes cutting the angled slit with a heated mandrel.13. The method of claim 10, wherein cutting an angled slit in the firstwall to form a partially detached portion of the first wall of thecatheter shaft includes cutting the angled slit in the first wall of thecatheter shaft proximally.
 14. The method of claim 13, wherein cuttingthe angled slit in the first wall of the catheter shaft proximallyincludes cutting the angled slit in the first wall of the catheter shaftproximally at an acute angle.
 15. The method of claim 10, wherein theelongated channel has a channel width and wherein the channel width issmaller than the diameter of the guidewire lumen.
 16. The method ofclaim 10, wherein the elongated channel has a channel width, and whereinthe channel width is substantially the same size as the diameter of theguidewire lumen.
 17. A method for forming a rapid exchange catheter, themethod comprising: forming a channel in a catheter having a guidewirelumen, wherein the channel opens a channel portion of the guidewirelumen to an outside of the catheter; cutting a slit extending from thechannel proximally at an angle to form a partially detached portion of awall of the catheter; and moving a distal end of the partially detachedportion radially of the wall of the catheter into the guidewire lumen toform a ramp, wherein the channel portion includes a pair of walls thatare separated from each other along a length of the channel portion andthe slit is cut into one of the pair of walls.
 18. The method of claim17, wherein cutting a slit extending from the channel proximally at anangle to form a partially detached portion of a wall of the catheterincludes cutting the slit proximally at an acute angle.
 19. The methodof claim 17, wherein the guidewire lumen has a diameter, wherein thechannel has a channel width, and wherein the channel width is smallerthan the diameter of the guidewire lumen.
 20. The method of claim 17,wherein the guidewire lumen has a diameter, wherein the channel has achannel width, and wherein the channel width is substantially the samesize as the diameter of the guidewire lumen.